can you do this for $15 a month with no contract, month to month? I am not being sarcastic, I am really asking and don't know...
Yes, I bought both the iPad 1 with 3G when it first came out, and now I have an iPad 2, also with 3G. My iPad 1 was AT&T, and now I have the Verizon model (which wasn't intentional, I bought it off craigslist and it just happened to be Verizon instead of AT&T.)
If you get the AT&T model iPad, the mobile data plan starts at $15 a month, and there is no contract. The mobile data plan for Verizon however starts at $20 a month, but you do get 4 times the data for $5 more. It's all month-to-month, and very easy to sign up for one month when you need 3G, and cancel the next, without any problems whatsoever.
I did have a first gen Mac Air, but gave it to my husband's neice to take to college with her. It just didn't suit my needs. I work with a lot of spreadsheets and really needed a laptop with a built-in numeric keyboard, and it's a lot easier to work with spreadsheets on a 17" screen. For work, I also use an HP, Apple doesn't do business well. And no, I am not about to install "boot camp" and for anyone who really works with numbers, USB keypads suck, big time.
The iPad fits most my other needs, especially nice for reading ebooks, and even better for traveling, enabling me to book hotel and other reservations "on the fly" and I really don't want to be forced to read or attempt to respond to an email on a cell phone, ever again. I use the ipad for texting as well, and casual gaming while having to sit waiting at the airport really makes the time fly.
The girl I gave my Mac Air wouldn't be able to use an iPad instead at her college. They don't make apps for the type of programs she uses in school. For her needs though, the Mac Air is wonderful.
It really depends though on your major and what programs you use for your schoolwork, if any. If you would just need it to type papers and study, yeah, you probably could use an iPad, but the on-screen keyboard isn't designed to enable typing speed. I've tested my typing speed, and I type over 100 words per minute normally, but haven't been able to score higher than 30 words per minute on my iPad, which to me, is tediously slow. Of course, they make keyboards for the iPad, but before I'd go that route, I personally would just stick with a laptop.